Projector

ABSTRACT

A projector includes: a light source; a light modulation device that modulates light emitted from the light source; an optical projection device that projects the light modulated by the light modulation device; a light path changing element (shift element) that is disposed between the light modulation device and the optical projection device and changes a light path of the light modulated by the light modulation device through fluctuation; and a cooling device that cools the light modulation device and the light path changing element (shift element).

CROSS REFERENCE TO RELATED APPLICATIONS

The entire disclosures of Japanese Patent Application No. 2015-199157filed Oct. 7, 2015, and Japanese Patent Application No. 2015-199158filed Oct. 7, 2015, are expressly incorporated by reference herein.

BACKGROUND

1. Technical Field

The present invention relates to a projector.

2. Related Art

In the related art, there are known projectors each including anillumination device, a light modulation device that modulates lightemitted from the illumination device and forms an image according toimage information, and an optical projection device that expands andprojects the image to a projection surface such as a screen (forexample, see JP-A-2001-312003).

The projector disclosed in JP-A-2001-312003 includes a color separationoptical device that separates a light flux emitted from a light sourceinto pieces of respective color light of red, green, and blue, threeliquid crystal panels that are installed for each of the pieces ofseparated color light, a prism that combines the color light modulatedby the three liquid crystal panels, an optical projection device thatprojects the combined light, and a cooling device that sends airintroduced from the outside of a casing to the liquid crystal panels tocool the liquid crystal panels. In the cooling device of the devices,cooling fans are installed according to the number of liquid crystalpanels. The cooling fans independently send cooling airs to thecorresponding liquid crystal panels.

Incidentally, high resolutions of projected images have recently beenrequested even in projectors. Accordingly, in order to cause theresolution of an image to be projected to be higher than the resolutionof a light modulation device such as a liquid crystal panel, a lightpath changing element that changes a light path of the light isconsidered to be installed between the prism and the optical projectiondevice and shift an axis of video light emitted from the lightmodulation device.

However, since the light path changing element is disposed between theprism and the optical projection device, the cooling device of theprojector disclosed in JP-A-2001-312003 may not cool the light pathchanging element. An increase in the size of the projector and highluminance result in an increase in the size of the light path changingelement, and thus a problem may arise in that the function of the lightpath changing element deteriorates due to heat generated in driving ofthe light path changing element.

Therefore, there is a request for a projector capable of supplying acooling gas to a plurality of cooling targets such as the lightmodulation device and the light path changing element.

When a projector including a light path changing element is used in anevent site such as an outdoor place, there is a concern of fats or dustsbased on smoke being attached to the light path changing element. Inthis case, there is a problem that driving of the light path changingelement is affected.

Therefore, there is a request for a projector in which dusts or the likeare rarely attached to the light path changing element.

SUMMARY

An advantage of some aspects of the invention is to provide a projectorcapable of supplying a cooling gas to a plurality of cooling targets ora projector capable of suppressing attachment of dusts to a light pathchanging element.

A projector according to an aspect of the invention includes: a lightsource; a light modulation device that modulates light emitted from thelight source; an optical projection device that projects the lightmodulated by the light modulation device; a light path changing elementthat is disposed between the light modulation device and the opticalprojection device and changes a light path of the light modulated by thelight modulation device through fluctuation; and a cooling device thatcools the light modulation device and the light path changing element.

A shift element changing the light path of the incident light can beexemplified as the light path changing element.

According to the aspect of the invention, since the cooling gas can besupplied to the light modulation device and the light path changingelement which are a plurality of cooling targets, it is possible toprevent the temperature of the light modulation device from beingincreased. Since the light path changing element is cooled by thecooling device, it is possible to prevent the temperature of the lightpath changing element from being increased due to the light incidentfrom the light modulation device.

In the aspect of the invention, it is preferable that the projectorfurther includes: a plurality of the light modulation devices; and alight combination device that combines and exits pieces of lightmodulated by the plurality of light modulation devices, the opticalprojection device projects the light exited from the light combinationdevice, and the light path changing element is disposed between thelight combination device and the optical projection device.

According to the aspect of the invention with this configuration, thelight path changing element is disposed between the light combinationdevice and the optical projection device. When the light path changingelement is cooled, the light combination device can be cooled along withthe light path changing element. Accordingly, it is possible to preventthe temperature of the light path changing element from being increaseddue to the light incident from the light combination device.

In the aspect of the invention, it is preferable that the cooling deviceincludes a cooling fan that sends a cooling gas and a duct member thatcirculates the cooling gas from the cooling fan in the plurality oflight modulation devices, and the duct member includes a sending portthat circulates the cooling gas toward the light path changing element.

According to the aspect of the invention with this configuration, sincethe duct member circulating the cooling gas in the light modulationdevice includes the sending port, it is not necessary to separatelyinstall the cooling device that cools the light path changing element.Thus, it is possible to miniaturize the cooling device, and thus it ispossible to miniaturize the projector.

In the aspect of the invention, it is preferable that the light pathchanging element includes a permanent magnet, an optical member thatchanges the light path of the light fluctuated and incident by thepermanent magnet, a holding portion that holds the optical member andthe permanent magnet, and a pair of coils that are disposed in theholding portion with the permanent magnet interposed therebetween.

Here, when power is supplied to one pair of coils disposed with thepermanent magnet interposed therebetween, the permanent magnet isdisplaced, and thus a magnetic force displacing the light path changingelement is generated and the temperature of the coils is increased. Inthis way, when the temperature of the coils is increased, the magneticforce of the coils generating the magnetic force is weakened in somecases.

In contrast, according to the aspect of the invention with theconfiguration described above, since the cooling gas is supplied to thelight path changing element, it is possible to prevent the temperatureof the light path changing element, that is, one pair of coils includedin the light path changing element, from being increased. Accordingly,since it is possible to prevent the magnetic force of the coilsinstalled in the light path changing element from being reduced, it ispossible to stabilize driving of the light path changing element.

In the aspect of the invention, it is preferable that the light pathchanging element includes a coil holding portion holding the one pair ofcoils and mounted on the holding portion, and the sending portcirculates at least a part of the cooling gas in the coil holdingportion.

According to the aspect of the invention with this configuration, sincethe coils are held to be fixed to the holding portions of the light pathchanging element by the coil holding portions and at least a part of thecooling gas is circulated in the coil holding portions, it is possibleto reliably cool the coil holding portions. Accordingly, by cooling thecoil holding portions, it is possible to cool the coils held by the coilholding portions and it is possible to prevent the temperature of thecoils from being increased.

In the aspect of the invention, it is preferable that the coil holdingportion includes a heat radiation portion.

A fin or the like can be exemplified as the heat radiation portion.

According to the aspect of the invention with this configuration, sincethe coil holding portions include the heat radiation portion, a heatradiation amount of the coil holding portions is greater than a heatradiation amount of the coil holding portions not including the heatradiation portion. Thus, by supplying the cooling gas to the heatradiation portions of the coil holding portions, it is possible to coolthe coil holding portions more reliably. Accordingly, it is possible toreliably cool the coils held in the coil holding portions and preventfrom the temperature of the coils from being increased.

In the aspect of the invention, it is preferable that the coil holdingportion includes an extension extending toward the sending port.

According to the aspect of the invention with this configuration, sincethe coil holding portion includes the extension, the heat radiation areaof the coil holding portion including the extension is greater than theheat radiation area of the coil holding portion not including theextension. Thus, since the cooling gas is supplied to the coil holdingportion (the extension), it is possible to cool the coil holding portionmore reliably. Accordingly, it is possible to reliably cool the coilheld in the coil holding portion and prevent the temperature of the coilfrom being increased.

In the aspect of the invention, it is preferable that the lightcombination device includes three incidence surfaces on which the lightvia the plurality of light modulation devices is incident, and one exitsurface through which the light incident from the three incidencesurfaces and combined is exited, the duct member includes a plurality ofducts that are installed to correspond to the plurality of lightmodulation devices and send the cooling gas circulated inside to thecorresponding light modulation devices, and of the plurality of ducts,the ducts corresponding to the light modulation devices disposed to beopposite to each other with the light combination device interposedtherebetween each include a branch portion that branches the cooling gascirculated inside and sends the cooling gas from the sending port.

The cross dichroic prism can be exemplified as the light combinationdevice.

According to the aspect of the invention with this configuration, it ispossible to supply the cooling gas to the light modulation device andthe light path changing element via two ducts according to the lightmodulation devices disposed to be opposite to each other with the lightcombination device interposed therebetween. That is, since the coolinggas is supplied from two sending ports to the light path changingelement, it is possible to reliably cool the light path changingelement. Since the cooling gas can be supplied to the light modulationdevice and the light path changing element without further installingthe duct circulating the cooling gas to the light path changing element,it is possible to miniaturize the cooling device, and thus it ispossible to miniaturize the projector.

In the aspect of the invention, it is preferable that the light pathchanging element includes two fluctuation members including thepermanent magnet and the one pair of coils, of the light modulationdevices disposed to be opposite to each other with the light combinationdevice interposed therebetween, one of the fluctuation members isdisposed on a side of one light modulation device and the otherfluctuation member is disposed on a side of the other light modulationdevice, and the one fluctuation member is disposed at a positionopposite to the other fluctuation member with the optical memberinterposed therebetween when viewed in an incidence direction of lighton the optical member.

According to the aspect of the invention with this configuration, theposition of one fluctuation member is close to the position of one lightmodulation device. The position of the other fluctuation member is closeto the position of the other light modulation device. Therefore, sincethe position of each of the light modulation devices disposed to faceone another is close to the position of each of the fluctuation members,it is possible to simplify the configuration of the branch portion thatcirculates the cooling gas from the duct corresponding to the closelydisposed light modulation device to the fluctuation member. Since thedistance from the branch portion of the duct portion to the sending portcan be shortened, it is possible to suppress a reduction of acirculation speed of the cooling gas circulated in the duct.Accordingly, it is possible to cool the light path changing element morereliably.

A projector according to another aspect of the invention includes: alight source; a light modulation device that modulates light emittedfrom the light source; an optical projection device that projects thelight modulated by the light modulation device; a light path changingelement that is disposed between the light modulation device and theoptical projection device and changes a light path of the lightmodulated by the light modulation device through fluctuation; anexterior casing that forms an exterior, and an internal casing in whichthe light path changing element is disposed.

The shift element changing the light path of the incident light can beexemplified as the light path changing element.

According to the aspect of the invention, since the light path changingelement is disposed in the internal casing, it is possible to preventdust from being attached to the light path changing element.Accordingly, it is possible to further improve luminance of an image tobe projected from the projector.

In the aspect of the invention, it is preferable that the lightmodulation device is disposed in the internal casing.

According to the aspect of the invention with his configuration, sincethe light modulation device and the light path changing element aredisposed in the internal casing, it is possible to prevent dust frombeing attached to the light modulation device and the light pathchanging element. Accordingly, it is possible to further improveluminance of an image to be projected from the projector.

In the aspect of the invention, it is preferable that the projectorfurther includes: a plurality of the light modulation devices; and alight combination device that combines and exits pieces of lightmodulated by the plurality of light modulation devices, the opticalprojection device projects the light exited from the light combinationdevice, and the light combination device is disposed in the internalcasing.

According to the aspect of the invention with this configuration, sincethe plurality of light modulation devices, the light path changingelement, and the light combination device are disposed in the internalcasing, it is possible to prevent dust from being attached to the lightpath changing element, the light path changing element, and the lightcombination device. Accordingly, it is possible to further improveluminance and saturation of an image to be projected from the projector.

In the aspect of the invention, it is preferable that the projectorfurther includes a support member that is disposed in the internalcasing and supports the light combination device, the light pathchanging element includes a permanent magnet, an optical member thatchanges the light path of the light fluctuated and incident by thepermanent magnet, a holding portion that holds the optical member andthe permanent magnet, a pair of coils that are disposed in the holdingportion with the permanent magnet interposed therebetween, a coilholding portion that holds the one pair of coils, and a heattransmission portion that comes into contact with the coil holdingportion, and the heat transmission portion comes into contact with thesupport member so that heat is transmittable to the support member.

Here, when power is supplied to one pair of coils disposed with thepermanent magnet interposed therebetween, the permanent magnet isdisplaced, and thus a magnetic force displacing the light path changingelement is generated and the temperature of the coils is increased. Inthis way, when the temperature of the coils is increased, the magneticforce of the coils generating the magnetic force is weakened in somecases.

In contrast, according to the aspect of the invention with theconfiguration described above, the heat transmission portion fixed tothe coil holding portion of the light path changing element comes intocontact with the support member. Therefore, when the heat of the coilsis increased, the heat of the coils is transmitted to the support membervia the heat transmission portion. Thus, it is possible to prevent thetemperature of one pair of coils included in the light path changingelement from being increased. Accordingly, since it is possible toprevent the magnetic force of the coils included in the light pathchanging element from being reduced, it is possible to stabilize drivingof the light path changing element.

In the aspect of the invention, it is preferable that the internalcasing is a sealed casing, the light combination device includes firstand second support surfaces that are located to be opposite to eachother and are connected to the support member, the support memberincludes a first support portion connected to the first support surfaceand a second support portion connected to the second support surface,and the heat transmission portion comes into contact with at least oneof the first and second support portions so that heat is transmittable.

According to the aspect of the invention with this configuration, theheat transmission portion comes into contact with at least one of thefirst and second support portions supporting the first and secondsupport surfaces of the light combination device. Therefore, when theheat of the coils is increased, the heat of the coils is transmitted tothe support member via the heat transmission portion. Thus, it ispossible to prevent the temperature of one pair of coils included in thelight path changing element from being increased. Accordingly, since itis possible to prevent the magnetic force of the coils included in thelight path changing element from being reduced, it is possible tostabilize the driving of the light path changing element.

In the aspect of the invention, it is preferable that the heattransmission portion comes into contact with the internal casing so thatheat is transmittable.

According to the aspect of the invention with this configuration, theheat transmission portion comes into contact with the internal casing sothat heat is transmittable. Therefore, when the heat of the coils isincreased, the heat of the coils is transmitted to the internal casingvia the heat transmission portion. Thus, it is possible to prevent thetemperature of one pair of coils included in the light path changingelement from being increased. Accordingly, since it is possible toprevent the magnetic force of the coils included in the light pathchanging element from being reduced, it is possible to stabilize thedriving of the light path changing element.

In the aspect of the invention, it is preferable that the internalcasing includes a heat transmission spot coming into contact with theheat transmission portion.

According to the aspect of the invention with this configuration, theheat transmission portion comes into contact with the heat transmissionspot of the internal casing. Therefore, when the heat of the coils isincreased, the heat of the coils is transmitted to the heat transmissionspot of the internal casing via the heat transmission portion. Thus, itis possible to reliably prevent the temperature of one pair of coilsincluded in the light path changing element from being increased.Accordingly, since it is possible to reliably prevent the magnetic forceof the coils included in the light path changing element from beingreduced, it is possible to reliably stabilize the driving of the lightpath changing element.

In the aspect of the invention, it is preferable that the projectorfurther includes a cooling device that is disposed in the internalcasing and circulates a cooling gas in the internal casing, and a partof the cooling gas is circulated in the support member.

According to the aspect of the invention with this configuration, sincethe cooling device is disposed in the internal casing, it is possible tocool the light modulation device, the light path changing device, andthe light combination device disposed in the internal casing. Since thecooling gas is circulated to the support member to which the heat of thecoils is transmitted via the heat transmission portion, it is possibleto reliably cool the support member. Accordingly, it is possible toprevent the temperature of one pair of coils included in the light pathchanging element from being increased.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic perspective view illustrating the exterior of aprojector according to a first embodiment of the invention.

FIG. 2 is a schematic diagram illustrating an overall configuration ofthe projector according to the first embodiment.

FIG. 3 is a perspective view illustrating an electric optical device anda cooling device of the projector according to the first embodiment.

FIG. 4 is a plan view illustrating the electric optical device and thecooling device according to the first embodiment.

FIG. 5 is a perspective view illustrating a shift element when viewedfrom a light incidence side according to the first embodiment.

FIG. 6 is a plan view illustrating the shift element when viewed from alight exit side according to the first embodiment.

FIG. 7 is a side view illustrating the shift element according to thefirst embodiment.

FIG. 8 is an exploded perspective view illustrating the shift elementaccording to the first embodiment.

FIG. 9 is a perspective view illustrating a cooling device according tothe first embodiment.

FIG. 10 is a plan view illustrating the cooling device according to thefirst embodiment.

FIG. 11 is a sectional view illustrating the cross-sectional surfaces ofthe electric optical device, the shift element, and the cooling deviceon a red light side according to the first embodiment.

FIG. 12 is a sectional view illustrating the cross-sectional surfaces ofthe electric optical device, the shift element, and the cooling deviceon a blue light side according to the first embodiment.

FIG. 13 is a perspective view illustrating a shift element of aprojector according to a second embodiment of the invention.

FIG. 14 is a perspective view illustrating a shift element of aprojector according to a third embodiment of the invention.

FIG. 15 is a schematic perspective view illustrating the exterior of aprojector according to a fourth embodiment of the invention.

FIG. 16 is a schematic diagram illustrating an overall configuration ofthe projector according to the embodiment.

FIG. 17 is a plan view illustrating a shift element of the projectorwhen viewed from a light incidence side according to the embodiment.

FIG. 18 is a plan view illustrating the shift element when viewed from alight exit side according to the embodiment.

FIG. 19 is a side view illustrating the shift element according to theembodiment.

FIG. 20 is an exploded perspective view illustrating the shift elementaccording to the embodiment.

FIG. 21 is a schematic diagram illustrating an overall configuration ofa circulation cooling device according to the embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

A first embodiment of the invention will be described with reference tothe drawings.

Exterior Configuration of Projector

FIG. 1 is a schematic perspective view illustrating a projector 1according to a first embodiment of the invention.

The projector 1 according to the embodiment is a projection type displayapparatus that modulates light emitted from an illumination device 31 tobe described below to form an image according to image information andexpands and projects the image to a projection surface such as a screen.

The projector 1 includes a shift element 5 that changes a light path ofincident light, as will be described below in detail. A cooling devicehas a function of cooling the shift element 5 in addition to a lightmodulation device to be described below.

As illustrated in FIG. 1, the projector 1 includes an exterior casing 2that forms the exterior appearance.

The exterior casing 2 has a substantially rectangular parallelepipedshape that has a top surface 21, a bottom surface 22, a front surface23, a rear surface 24, and left and right side surface portions 25 and26.

In the top surface 21, an opening (not illustrated) is formed todetachably mount light source devices 31A and 31B to be described belowon the inside of the exterior casing 2. The opening is covered with acover member 212.

Although not illustrated, leg portions coming into contact with aninstallation surface of an installation stand when placed on theinstallation surface of the installation stand are installed on thebottom surface 22.

An opening 231 in which a part of the optical projection device 35included in an image forming device 3 to be described below is exposedis formed in the front surface 23.

Although the others are not illustrated, an inlet port introducing anair outside the exterior casing 2 into the inside is formed on the rightside surface 26, and an outlet port discharging the air inside theexterior casing 2 is formed on the left side surface 25.

Internal Configuration of Projector

FIG. 2 is a schematic diagram illustrating an internal configuration ofthe projector 1.

The projector 1 includes not only the exterior casing 2 but also animage forming device 3 and a cooling device 4 disposed in the exteriorcasing 2, as illustrated in FIG. 2. Additionally, although notillustrated, the projector 1 includes a control device that controls theprojector 1 and a power device that supplies power to electroniccomponents included in the projector 1.

Configuration of Image Forming Device

The image forming device 3 forms and projects an image according toimage information input from the control device. The image formingdevice 3 includes an illumination device 31, a uniformalization device32, a color separation device 33, an electric optical device 34, anoptical projection device 35, and an optical component casing 36.

Of the devices, the optical component casing 36 is a box-like casing inwhich an illumination light axis Ax is set. The illumination device 31,the uniformalization device 32, and the color separation device 33 aredisposed at positions on the illumination light axis Ax inside theoptical component casing 36. The electric optical device 34 and theoptical projection device 35 are located outside the optical componentcasing 36 and are disposed according to the illumination light axis Ax.

The illumination device 31 includes a pair of light source devices 31Aand 31B and a reflection mirror 31C disposed between the pair of lightsource devices 31A and 31B.

The pair of light source devices 31A and 31B each include a light sourcelamp 311, a reflector 312, and a housing body 313 that houses the lightsource lamp 311 and the reflector 312. The light source devices 31A and31B emit light toward the reflection mirror 31C.

The reflection mirror 31C reflects the light incident from the lightsource devices 31A and 31B in the same direction so that the light isaccordingly incident on the uniformalization device 32.

The uniformalization device 32 uniformalizes illuminance in anorthogonal plane to a central axis of a light flux emitted from theillumination device 31. The uniformalization device 32 includes a cinemafilter 321, a first lens array 322, a UV filter 323, a second lens array324, a polarization conversion element 325, and a superimposition lens326.

Of the elements, the polarization conversion element 325 arrangespolarization directions of the incident light in one kind of direction.

The color separation device 33 separates the light flux incident fromthe uniformalization device 32 into three pieces of color light of red(R), green (G), and blue (B). The color separation device 33 includesdichroic mirrors 331 and 332, reflection mirrors 333 to 336, and relaylenses 337 to 339.

The electric optical device 34 modulates the pieces of separated colorlight according to image information, and then combines the pieces ofmodulated color light. The electric optical device 34 includes fieldlends 340, liquid crystal panels 341 (red, green, and blue liquidcrystal panels are referred to as liquid crystal panels 341R, 341G, and341B, respectively) serving as light modulation devices installed forthe respective pieces of color light, incidence-side polarization plates342, exit-side polarization plates 343, optical compensation plates 344,and one color combination device 345. Of the elements, the colorcombination device 345 corresponds to a light combination deviceaccording to the invention.

The shift element 5 increases the resolution of a projection image byperiodically shifting a light path of light emitted by the colorcombination device 345.

The configurations of the electric optical device 34 and the shiftelement 5 will be described below in detail.

The optical projection device 35 is a projection lens that expands thelight flux (which is a light flux forming an image) combined by thecolor combination device 345 and projects the light flux to theprojection surface. An assembled lens in which a plurality of lenses aredisposed in a barrel can be adopted as the optical projection device 35.

In the following drawings and description, a Z direction indicates atravelling direction (projection direction) of the light exited from thecolor combination device 345, and X and Y directions indicate directionsorthogonal to the Z direction and orthogonal to each other. Of thedirections, the Y direction indicates an upward side which is anopposite direction to the vertical direction (that is, a directionoriented from the bottom surface 22 to the top surface 21 of theexterior casing 2) in a case in which the projector 1 is disposed sothat the Z direction is oriented in the horizontal direction in a planview. The X direction indicates a direction oriented from the left tothe right when viewed in the Z direction (light traveling direction).

Configuration of Electric Optical Device

FIG. 3 is a perspective view illustrating the electric optical device 34and the cooling device 4. FIG. 4 is a plan view illustrating theelectric optical device 34 and the cooling device 4 when viewed in the Ydirection. In FIGS. 3 and 4, the electric optical device 34 isillustrated in a state in which the field lenses 340 are detached.

Of the constituent elements of the electric optical device 34, theliquid crystal panels 341 (341R, 341G, and 341B), the exit-sidepolarization plates 343, and the optical compensation plates 344 aremounted on the color combination device 345 by holding members. Theliquid crystal panels 341, the exit-side polarization plates 343, theoptical compensation plates 344, and the color combination device 345are configured to form an integrated prism unit, as illustrated in FIGS.3 and 4.

The color combination device 345 configured to form the prism unit isconfigured by a substantially quadrangular cross dichroic prism. Thecolor combination device 345 has six surfaces 3451 to 3456. Of thesurfaces, prism bases 347U and 347L (see FIGS. 3 and 11) respectivelycome into contact with the surface 3451 in the Y direction of the colorcombination device 345 and the surface 3452 on the opposite side to theY direction, and thus the color combination device 345 is supported.

The surface 3453 in the X direction of the color combination device 345,the surface 3454 on the opposite side in the X direction, and thesurface 3455 on the opposite side in the Z direction are incidencesurfaces of pieces of red, blue, and green modulated light. The surface3456 in the Z direction is an exit surface. The liquid crystal panels341R, 341G, and 341B are held by holding members 346 (a red holdingmember 346R, a green holding member 346G, and a red holding member 346B)to face the incidence surfaces (surfaces 3453 to 3455). Accordingly, theliquid crystal panels 341, the incidence-side polarization plates 342,the exit-side polarization plates 343, and the optical compensationplates 344 can be integrated.

Configuration of Shift Element

FIG. 5 is a perspective view illustrating a fixing member 360 and theshift element 5 when viewed in the opposite direction to the Zdirection.

The fixing member 360 is a portion that forms a part of the opticalcomponent casing 36 and fixes the shift element 5. The fixing member 360is disposed at a position facing the optical projection device 35 in theoptical component casing 36. The shift element 5 is fixed to a surface3601 in the opposite direction to the Z direction of the fixing member360, as illustrated in FIG. 5. Specifically, the shift element 5 isfixed to the fixing member 360 so that the shift element 5 is fixed tobe disposed between the color combination device 345 and the opticalprojection device 35.

FIG. 6 is a plan view illustrating the shift element 5 when viewed inthe Z direction. FIG. 7 is a side view illustrating the shift element 5when viewed in the X direction. FIG. 8 is an exploded perspective viewillustrating the shift element 5.

The shift element 5 corresponds to a light path changing elementaccording to the invention and has a function of changing (shifting) alight path of the light incident on the shift element 5 and exited fromthe shift element 5 through fluctuation of the shift element 5. Asillustrated in FIGS. 5 to 8, the shift element 5 includes an opticalmember 51, a rim 52, permanent magnets 53, a first frame 54, a secondframe 55, and pairs of coil holding portions 56 and 57.

Of the elements, the optical member 51 is configured as a transparentmember that has transmittance and is configured of a rectangular plateglass in the embodiment.

Configuration of Rim

The rim 52 has a function of holding the optical member 51 and thepermanent magnets 53. As illustrated in FIG. 5, the rim 52 is configuredin a rectangular plate shape that has four corners CR1 to CR4. Anopening 521 in which the optical member 51 is inserted is formed in thesubstantially middle portion of the rim 52, as illustrated in FIG. 8.Fitting grooves 522 and 523 in which the permanent magnets 53 areinserted are formed at a position in the Y direction of the opening 521of the rim 52 and a position in the opposite direction to the Ydirection. Of the fitting grooves 522 and 523, the fitting groove 522 isformed in the opposite direction to the X direction relative to thefitting groove 523.

Positioning protrusions 524 protruding in the opposite direction to theZ direction are formed at end edges in the Y direction of the fittinggroove 522 of the rim 52 and in the opposite direction to the Xdirection. Positioning protrusions 525 protruding in the oppositedirection to the Z direction are formed at end edges in the oppositedirection to the Y direction of the fitting groove 523 of the rim 52 andin the X direction. Further, positioning protrusions 526 and 527protruding in the Z direction are formed at position corresponding tothe positioning protrusions 524 and 525 on the surface of the rim 52 inthe Z direction.

In other words, the positioning protrusions 524 and 526 in the Ydirection are formed near the corner CR3 among the four corners CR1 toCR4 of the rim 52. The positioning protrusions 525 and 527 in theopposite direction to the Y direction are formed near the corner CR2which is a diagonal corner of the corner CR3.

As illustrated in FIG. 8, the permanent magnets 53 are formed in arectangular column shape. The permanent magnet 53 (permanent magnet 531)is fitted in the fitting groove 522 and the permanent magnet 53(permanent magnet 532) is fitted in the fitting groove 523. In this way,the permanent magnets 531 and 532 are fixed to the rim 52.

Configuration of First Frame

The first frame 54 is disposed in the opposite direction to the Zdirection of the rim 52 and has a function of interposing the rim 52along with the second frame 55. The first frame 54 is formed in arectangular plate shape and an opening 541 is formed in thesubstantially middle of the first frame 54. The opening 541 is formed insubstantially the same shape as the optical member 51. Accordingly,light incident from the opening 541 is incident on the optical member51.

Through holes 542 are formed at end edges in the Y direction of thefirst frame 54 and in the opposite direction to the X direction, andthrough holes 543 are formed at end edges in the opposite direction tothe Y direction of the first frame 54 and in the X direction. Thepositioning protrusions 524 of the rim 52 are inserted into the throughholes 542 and the positioning protrusions 525 are inserted into thethrough holes 543.

Configuration of Second Frame

The second frame 55 is disposed in the Z direction of the rim 52 and hasa function of interposing the rim 52 along with the first frame 54. Thesecond frame 55 is formed in a rectangular plate shape and an opening551 is formed in the substantially middle of the second frame 55. Theopening 551 is formed in substantially the same shape as the opticalmember 51.

Through holes 552 are formed at end edges in the Y direction of thesecond frame 55 and in the opposite direction to the X direction, andthrough holes 553 are formed at end edges in the opposite direction tothe Y direction of the second frame 55 and in the X direction. Thepositioning protrusions 526 of the rim 52 are inserted into the throughholes 552 and the positioning protrusions 527 are inserted into thethrough holes 553.

The second frame 55 further includes extensions 554 to 557 extendingfrom the corners to the outside of the second frame 55. Through holes5541, 5551, 5561, and 5571 through which screws S1 are inserted areformed in the extensions 554 to 557. By screwing the screws S1 to thefixing member 360, the shift element 5 is fixed to the fixing member360, as illustrated in FIG. 5.

In this configuration, the first frame 54 and the second frame 55interpose the rim 52. The rim 52, the first frame 54, and the secondframe 55 correspond to a rim according to the invention.

Configuration of Coil Holding Portions

One pair of coil holding portions 56 and one pair of coil holdingportions 57 each include an air-core coil CL corresponding to a coilaccording to the invention therein. When power is supplied to theair-core coil CL, the air-core coil CL displaces the permanent magnet 53and further generates a magnetic force that displaces the shift element5. Of the portions, one pair of coil holding portions 56 includes a coilholding portion 561 fixed to the first frame 54 and a coil holdingportion 562 fixed to the second frame 55.

Holes 5611 and 5621 are formed in the coil holding portions 561 and 562,respectively. The positioning protrusions 524 of the rim 52 are fittedinto the holes 5611 through the through holes 542 of the first frame 54.On the other hand, the positioning protrusions 526 of the rim 52 arefitted into the holes 5621 through the through holes 552 of the secondframe 55. Accordingly, the coil holding portion 561 is fixed to thefirst frame 54 and the coil holding portion 562 is fixed to the secondframe 55.

One pair of coil holding portions 57 includes a coil holding portion 571fixed to the first frame 54 and a coil holding portion 572 fixed to thesecond frame 55. Holes 5711 and 5721 are formed in the coil holdingportions 571 and 572, respectively. The positioning protrusions 525 ofthe rim 52 are fitted into the holes 5711 through the through holes 543of the first frame 54. On the other hand, the positioning protrusions527 of the rim 52 are fitted into the holes 5721 through the throughholes 553 of the second frame 55. Accordingly, the coil holding portion571 is fixed to the first frame 54 and the coil holding portion 572 isfixed to the second frame 55.

One pair of coil holding portions 56, the air-core coil CL included inthe one pair of coil holding portions 56, and the permanent magnet 531correspond to one fluctuation member according to the invention. Onepair of coil holding portions 57, the air-core coil CL included in theone pair of coil holding portions 57, and the permanent magnet 532correspond to the other fluctuation member according to the invention.

In this way, the coil holding portions 561 and 562 of one pair of coilholding portions 56 are disposed near the corner CR3 in the Y directionin the opposite direction to the X direction and at superimposingpositions and orientation. On the other hand, the coil holding portions571 and 572 of one pair of coil holding portions 57 are disposed nearthe corner CR2 in the X direction and the opposite direction to the Ydirection and at superimposing positions and orientation in a case inwhich the shift element 5 is viewed in the Z direction. In other words,when the shift element 5 fixed to the fixing member 360 is viewed in theopposite direction to the Z direction, one pair of coil holding portions56 are disposed on the side of the liquid crystal panel 341B and onepair of coil holding portions 57 are disposed on the side of the liquidcrystal panel 341R.

The rim 52, the first frame 54, and the second frame 55, one pair ofcoil holding portions 56, and one pair of coil holding portions 57 areformed of metal having heat conductivity and are formed of aluminum inthe embodiment. Accordingly, in a case in which the temperature of theair-core coil CL increases, heat of the rim 52, the first frame 54, thesecond frame 55, and the air-core coils CL of one pair of coil holdingportions 56 and one pair of coil holding portions 57 is transmitted.

Power supply portions 3602 mounted on the fixing member 360 areconnected to the coil holding portions 561, 562, 571, and 572 (see FIG.5). The power supply portions 3602 supply power to the air-core coils CLvia the coil holding portions 561, 562, 571, and 572 to displace thepermanent magnets 531 and 532 and further generate a magnetic force todisplace the shift element 5.

Specifically, when the permanent magnets 531 and 532 mounted on the rim52 are displaced, the shift element 5 is moved in approaching andseparating directions relative to the surface 3601 of the fixing member360 at a rotational angle L1 illustrated in FIG. 6, so that the angle ofthe optical member 51 is inserted into the opening 521 of the rim 52 ischanged.

In other words, by supplying power to the coil holding portions 561,562, 571, and 572, it is possible to change the light path of the lightincident on the optical member 51 and exited from the optical member 51.

Configuration of Cooling Device

FIG. 9 is a perspective view illustrating the cooling device 4 whenviewed in the Y direction. FIG. 10 is a plan view illustrating thecooling device 4 when viewed in the Y direction.

The cooling device 4 has a function of sending a cooling gas to cool theliquid crystal panels 341 (341R, 341G, and 341B) and the shift element5. As illustrated in FIGS. 9 and 10, the cooling device 4 includescooling fans 41 (cooling fans corresponding to the liquid crystal panels341R, 341G, and 341B are referred to as cooling fans 41R, 41G, and 41B)and a duct member 42. Of these elements, the cooling fan 41 sucks thecooling gas around the cooling fan 41 and supplies the cooling gas tothe liquid crystal panel 341 and the shift element 5 via the duct member42.

The cooling fan 41 is configured by a sirocco fan. However, theinvention is not limited thereto. The cooling fan 41 may be configuredby an axial fan.

Configuration of Duct Member

The duct member 42 guides the cooling gas sent from each cooling fan 41not only to the corresponding liquid crystal panel 341, thecorresponding incidence-side polarization plate 342, the correspondingexit-side polarization plate 343, and the corresponding opticalcompensation plate 344 but also to the shift element 5. The duct member42 includes a first duct portion 43, a second duct portion 44, a thirdduct portion 45, and a connection portion 46.

Configuration of First Duct Portion

The first duct portion 43 has a function of supplying the cooling gasfrom the cooling fan 41R to the liquid crystal panel 341R and the coilholding portion 57 in the shift element 5. The first duct portion 43includes a branch portion 431, a sending port 432 that sends the partialcooling gas branched by the branch portion 431 to the red liquid crystalpanel 341R, and a sending port 433 that sends the other branched partialcooling gas to the coil holding portion 57 of the shift element 5.

An end 434 of the first duct portion 43 in the X direction is connectedto an ejection port of the cooling fan 41R. A protrusion 435 of thefirst duct portion 43 has a shape extending in the Y direction and thesending port 432 is formed at the end of the protrusion 435 in the Ydirection. A rectification portion 436 is installed at the end of theprotrusion 435 in the opposite direction to the Y direction. Therectification portion 436 is formed in a substantially arc shape and hasa function of circulating the cooling gas from the cooling fan 41Rsmoothly in the Y direction.

The sending port 432 is disposed at a position corresponding to theliquid crystal panel 341R. Accordingly, the cooling gas is circulated tothe liquid crystal panel 341R through the sending port 432.

As illustrated in FIGS. 9 and 10, the first duct portion 43 has anextension 437 extending from the branch portion 431 in the Z direction.The sending port 433 is formed in the extension 437. An opening 4372 isformed in a surface 4371 of the extension 437 in the opposite directionto the Z direction. Apart of the cooling gas supplied from the coolingfan 41R is circulated in the opening 4372. That is, the branch portion431 is formed by the surface 4371 and the opening 4372.

The sending port 433 corresponds to a sending port according to theinvention and is disposed at a position facing the coil holding portion57 of the shift element 5.

Configuration of Second Duct Portion

The second duct portion 44 has a function of supplying the cooling gasfrom the cooling fan 41G to the liquid crystal panel 341G. The secondduct portion 44 includes a sending port 442 that sends the cooling gasto the green liquid crystal panel 341G.

An end 444 of the second duct portion 44 in the opposite direction tothe Z direction is connected to an ejection port of the cooling fan 41G.The sending port 442 is formed in a protrusion 445 of the second ductportion 44. A rectification portion 446 is installed at the end of theprotrusion 445 in the opposite direction to the Y direction. Therectification portion 446 is formed in a substantially arc shape and hasa function of circulating the cooling gas from the cooling fan 41Gsmoothly in the Y direction.

The sending port 442 is disposed at a position corresponding to theliquid crystal panel 341G. Accordingly, the cooling gas is circulated tothe liquid crystal panel 341G through the sending port 442.

Configuration of Third Duct Portion

The third duct portion 45 has a function of supplying the cooling gasfrom the cooling fan 41B to the liquid crystal panel 341B and the coilholding portion 56 in the shift element 5. The third duct portion 45includes a branch portion 451, a sending port 452 that sends the partialcooling gas branched by the branch portion 451 to the blue liquidcrystal panel 341B, and a sending port 453 that sends the other branchedpartial cooling gas to the coil holding portion 56 of the shift element5.

An end 454 of the third duct portion 45 in the opposite direction to theZ direction is connected to an ejection port of the cooling fan 41B. Aprotrusion 455 of the third duct portion 45 has a shape extending in theY direction and the sending port 452 is formed at the end of theprotrusion 455 in the Y direction. A rectification portion 456 isinstalled at the end of the protrusion 455 in the opposite direction tothe Y direction. The rectification portion 456 is formed in asubstantially arc shape and has a function of circulating the coolinggas from the cooling fan 41B smoothly in the Y direction.

The sending port 452 is disposed at a position corresponding to theliquid crystal panel 341B. Accordingly, the cooling gas is circulated tothe liquid crystal panel 341B through the sending port 452.

As illustrated in FIGS. 9 and 10, the third duct portion 45 has anextension 457 extending from the branch portion 451 in the Z direction.The sending port 453 is formed in the extension 457. An opening 4572 isformed in a surface 4571 of the extension 457 in the opposite directionto the Z direction. Apart of the cooling gas supplied from the coolingfan 41B is circulated in the opening 4572. That is, the branch portion451 is formed by the surface 4571 and the opening 4572.

The sending port 453 corresponds to a sending port according to theinvention and is disposed at a position facing the coil holding portion56 of the shift element 5.

Circulation Direction of Cooling Gas

FIG. 11 is a sectional view illustrating a cross-sectional surface takenalong the line A1-A1 of FIG. 4 when the electric optical device 34 andthe cooling device 4 are cut. FIG. 12 is a sectional view illustrating across-sectional surface taken along the line B1-B1 of FIG. 4 when theelectric optical device 34 and the cooling device 4 are cut.

The cooling gas sent from the cooling fan 41G is sent in the Y directionfrom the sending port 442 via the second duct portion 44 to be suppliedto the liquid crystal panel 341G, as illustrated in FIGS. 11 and 12.

The cooling gas sent from the cooling fan 41R is introduced into thefirst duct portion 43, as illustrated in FIG. 11. Of the cooling gas,the partial cooling gas branched by the branch portion 431 is sent fromthe sending port 432 in the Y direction to be supplied to the liquidcrystal panel 341R. On the other hand, the other partial cooling gasbranched by the branch portion 431 is circulated in the extension 437,is sent in the Y direction from the sending port 433 formed in theextension 437, and is supplied to a region of the shift element 5 in theX direction.

Here, a rectification portion 4373 inclined in the Z direction is formedat the end of the extension 437 in the Z direction, as illustrated inFIG. 11. Therefore, the cooling gas circulated in the extension 437 isspread to be sent in the Z direction when the cooling gas is sent fromthe sending port 433. Specifically, the cooling gas sent from thesending port 433 is circulated to a surface of the shift element 5 inthe Z direction and a surface of the shift element 5 in the oppositedirection to the Z direction. More specifically, the cooling gas sentfrom the sending port 433 is circulated to a surface of the coil holdingportion 571 in the opposite direction to the Z direction and a surfaceof the coil holding portion 572 in the Z direction.

The cooling gas sent from the cooling fan 41B is introduced into thethird duct portion 45, as illustrated in FIG. 12. Of the cooling gas,the partial cooling gas branched by the branch portion 451 is sent fromthe sending port 452 in the Y direction to be supplied to the liquidcrystal panel 341B. On the other hand, the other partial cooling gasbranched by the branch portion 451 is circulated in the extension 457,is sent in the Y direction from the sending port 453 formed in theextension 457, and is supplied to a region of the shift element 5 in theX direction.

Here, a rectification portion 4573 inclined in the Z direction is formedat the end of the extension 457 in the Z direction, as illustrated inFIG. 12. Therefore, the cooling gas circulated in the extension 457 isspread to be sent in the Z direction when the cooling gas is sent fromthe sending port 453. Specifically, the cooling gas sent from thesending port 453 is circulated to a surface of the shift element 5 inthe Z direction and a surface of the shift element 5 in the oppositedirection to the Z direction. More specifically, the cooling gas sentfrom the sending port 453 is circulated to a surface of the coil holdingportion 571 in the opposite direction to the Z direction and a surfaceof the coil holding portion 572 in the Z direction.

In this way, the cooling gases circulated in the region of the shiftelement 5 in the X direction and the region in the opposite direction tothe X direction are circulated along the coil holding portions 56 and 57to cool the coil holding portions 56 and 57 (particularly, the air-corecoils CL) and also cool the permanent magnet 53 interposed between thecoil holding portions 56 and 57. In this way, the shift element 5 iscooled, and thus driving of the shift element 5 is stabilized.

Advantages of First Embodiment

There are the following advantages of the projector 1 according to theabove-described embodiment.

Since the cooling gas can be supplied to the liquid crystal panels 341and the shift element 5 which are the plurality of cooling targets, itis possible to prevent the temperature of the liquid crystal panels 341from being increased. Since the shift element 5 is cooled by the coolingdevice 4, it is possible to prevent the temperature of the shift element5 from being increased due to light incident from the liquid crystalpanels 341.

Since the shift element 5 is disposed between the color combinationdevice 345 and the optical projection device 35, the color combinationdevice 345 can also be cooled along with the shift element 5 at the timeof the cooling of the shift element 5. Accordingly, it is possible toprevent the temperature of the shift element 5 from being increased bylight incident from the color combination device 345.

Since the duct member 42 circulating the cooling gas in the liquidcrystal panels 341 includes the sending ports 433 and 453, it is notnecessary to separately provide a cooling device cooling the shiftelement 5. Thus, it is possible to miniaturize the cooling device 4 andfurther miniaturize the projector 1.

Here, when power is supplied to one pair of air-core coils CL disposedwith the permanent magnet 53 interposed therebetween, the permanentmagnet 53 is displaced, the magnetic force displacing the shift element5 is generated, and thus the temperature of the air-core coils CL isincreased. Thus, when the temperature of the air-core coils CL isincreased, the magnetic force of the air-core coils CL generating themagnetic force is weakened in some cases.

In the embodiment, however, since the cooling gas is supplied to theshift element 5, it is possible to prevent the temperature of the shiftelement 5, that is, one pair of air-core coils CL included in the shiftelement 5, from being increased. Accordingly, since the reduction in themagnetic force of the air-core coils CL installed in the shift element 5can be suppressed, it is possible to stabilize driving of the shiftelement 5.

The air-core coils CL are fixed to the first frame 54 and the secondframe 55 forming the holding portions of the shift element 5 to be heldby one pair of coil holding portions 56 and one pair of coil holdingportions 57, and at least part of the cooling gas is circulated in thecoil holding portions 56 and 57. Therefore, it is possible to cool thecoil holding portions 56 and 57. Accordingly, by cooling the coilholding portions 56 and 57, it is possible to cool the air-core coils CLheld by the coil holding portions 56 and 57, and thus it is possible toprevent the temperature of the air-core coils CL from being increased.

The cooling gas can be supplied to the liquid crystal panels 341R and341B and the shift element 5 via the two duct portions 43 and 45according to the liquid crystal panels 341R and 341B disposed to beopposite to each other with the color combination device 345 interposedtherebetween. That is, since the cooling gas is supplied from the twosending ports 433 and 453 to the shift element 5, it is possible toreliably cool the shift element 5. Since the cooling gas can be suppliedto the liquid crystal panels 341 and the shift element 5 without furtherproviding a duct that circulates a cooling gas to the shift element 5,it is possible to miniaturize the cooling device 4 and furtherminiaturize the projector 1.

The positions of the air-core coil CL, one pair of coil holding portions56, and the permanent magnet 531 forming one fluctuation member areclose to the position of one liquid crystal panel 341B. The positions ofthe air-core coil CL, one pair of coil holding portions 57, and thepermanent magnet 532 forming the other fluctuation member are close tothe position of the other liquid crystal panel 341R. Therefore, sincethe position of each of the liquid crystal panels 341R and 341B disposedto face one another is close to the position of each of the fluctuationmembers, it is possible to simplify the configuration of the branchportions 431 and 451 that circulate the cooling gas from the ductportions 43 and 45 corresponding to the closely disposed liquid crystalpanels 341R and 341B to the fluctuation member. Since the distances fromthe branch portions 431 and 451 of the duct portions 43 and 45 to thesending ports 433 and 453 can be shortened, it is possible to suppress areduction of a circulation speed of the cooling gas circulated in theduct portions 43 and 45. Accordingly, it is possible to cool the shiftelement 5 more reliably.

Second Embodiment

Next, a second embodiment of the invention will be described.

A projector 1A according to the embodiment has the same configuration asthe projector 1, but is different from the projector 1 in that the shapeof a shift element included in an electric optical device is different.In the following description, the same reference numerals are given tothe same portions as the above-described portions or substantially thesame portions and the description thereof will be omitted.

FIG. 13 is a perspective view illustrating a shift element 5A of theprojector 1A according to the embodiment.

The shift element 5A corresponds to a light path changing elementaccording to the invention and has a function of changing a light pathof incident light. The shift element 5A includes an optical member 51, arim 52, permanent magnets (not illustrated), a first frame 54, a secondframe 55, one pair of coil holding portions 56A, and one pair of coilholding portions 57, as illustrated in FIG. 13. In the embodiment, onlythe configuration of the coil holding portions 56A is different.Therefore, only the coil holding portions 56A will be described below indetail.

One pair of coil holding portions 56A include an air-core coil CLtherein and are formed of aluminum having heat conductivity, as in thecoil holding portions 56. In the one pair of coil holding portions 56A,a coil holding portion 561A in the opposite direction to the Z directionis formed in a substantial L shape, as illustrated in FIG. 13.Specifically, the coil holding portion 561A includes an extension 56A1extending along the side edge of the first frame 54 in the oppositedirection to the X direction on the side of the sending port 453, thatis, in the opposite direction to the Y direction. In this configuration,a heat radiation area of the coil holding portion 561A is greater thanheat radiation areas of the other coil holding portions 562, 571, and572.

When a cooling gas is sent from the sending port 453 to the coil holdingportion 561A, the cooling gas is circulated along the surface of theextension 56A1 of the coil holding portion 561A in the oppositedirection to the Z direction to cool the coil holding portion 561A.

Advantages of Second Embodiment

The projector 1A according to the above-described embodiment has thefollowing advantages in addition to the same advantages as those of theprojector 1.

A distance from the sending port 433 to the coil holding portion 57 isgreater than a distance from the sending port 453 to the coil holdingportion 56. There is a possibility that a part of the cooling gas ofwhich the temperature increases due to cooling of the coil holdingportion 57 is circulated in the coil holding portions 56. Accordingly,cooling efficiency of the coil holding portions 56 is assumed to belower than cooling efficiency of the coil holding portions 57.

Here, since the coil holding portion 561A includes the extension 56A1,the heat radiation area of the coil holding portion 561A including theextension 56A1 is greater than the heat radiation area of the coilholding portion 561 not including the extension 56A1. Thus, since thecooling gas is supplied to the coil holding portion 561A (the extension56A1), it is possible to cool the coil holding portion 561A morereliably. Accordingly, it is possible to reliably cool the air-core coilCL held in the coil holding portion 561A and prevent the temperature ofthe air-core coil CL from being increased.

Third Embodiment

Next, a third embodiment of the invention will be described.

A projector 1B according to the embodiment has the same configuration asthe projector 1, but is different from the projector 1 in that the shapeof a shift element included in an electric optical device is different.In the following description, the same reference numerals are given tothe same portions as the above-described portions or substantially thesame portions and the description thereof will be omitted.

FIG. 14 is a perspective view illustrating a shift element 5B of theprojector 1B according to the embodiment.

The shift element 5B corresponds to a light path changing elementaccording to the invention and has a function of changing a light pathof incident light. The shift element 5B includes an optical member 51, arim 52, permanent magnets (not illustrated), a first frame 54, a secondframe 55, one pair of coil holding portions 56B, and one pair of coilholding portions 57B, as illustrated in FIG. 14. In the embodiment, onlythe configurations of the coil holding portions 56B and 57B aredifferent. Therefore, only the coil holding portions 56B and 57B will bedescribed below in detail.

One pair of coil holding portions 56B and one pair of coil holdingportions 57B include air-core coils CL therein and are formed ofaluminum having heat conductivity, as in the coil holding portions 56.Each of the coil holding portions 561B and 562B includes a plurality ofrectangular plate-shaped fins 56B1 corresponding to a heat radiationportion according to the invention. On the other hand, each of the coilholding portions 571B and 572B also include a plurality of rectangularplate-shaped fins 57B1. In this configuration, a heat radiation area ofthe coil holding portion 56B and 57B is greater than heat radiation areaof one pair of coil holding portions 56 and 57 according to the firstembodiment.

When a cooling gas is sent from the sending ports 433 and 453 to thepairs of coil holding portions 56B and 57B, the cooling gas iscirculated between the plurality of fins 56B1 and 57B1 of the one pairof coil holding portions 56B and 57B to cool the pairs of coil holdingportion 56B and 57B.

Advantages of Third Embodiment

The projector 1B according to the above-described embodiment has thefollowing advantages in addition to the same advantages as those of theprojector 1.

Since one pair of coil holding portions 56B and one pair of coil holdingportions 57B include the fins 56B1 and 57B1 as the heat radiationportions, a heat radiation amount of the one pair of coil holdingportions 56B and the one pair of coil holding portions 57B is greaterthan a heat radiation amount of the coil holding portions 56 and 57 notincluding the fins 56B1 and 57B1. Thus, since the cooling gas issupplied to the fins 56B1 and 57B1 of one pair of coil holding portions56B and one pair of coil holding portions 57B, it is possible to coolone pair of coil holding portions 56B and one pair of coil holdingportions 57B more reliably. Accordingly, it is possible to reliably coolthe air-core coils CL held in one pair of coil holding portions 56B andone pair of coil holding portions 57B and prevent the temperature of theair-core coils CL from being increased.

Modifications of Embodiments

The invention is not limited to the foregoing embodiments, andmodifications, improvements, and the like are included in the inventionwithin the scope of the invention.

In the foregoing embodiments, the cooling device 4 is assumed to includethe cooling fans 41R, 41G, and 41B respectively connected to the firstto third duct portions 43 to 45. However, the invention is not limitedthereto. For example, the number of cooling fans 41 may be one or two.In this case, the first to third duct portions 43 to 45 may have anyshape as long as the cooling gas can be supplied to the first to thirdduct portions 43 to 45.

In the foregoing embodiments, the shift element 5 is assumed to includethe optical member 51, the rim 52, the permanent magnet 53, the firstframe 54, the second frame 55, one pair of coil holding portions 56, andone pair of coil holding portions 57. However, the invention is notlimited thereto. For example, the first frame 54 and the second frame 55may be integrated. One pair of coil holding portions 56 and one pair ofcoil holding portions 57 are included, but one of the pairs of coilholing portions may be included.

That is, any configuration can be used as long as power can be suppliedto the air-core coils CL held by the coil holding portions 56 and 57,the shift element 5 can be fluctuated, and the light path of the lightincident on the optical member 51 can be changed.

In the foregoing embodiments, the air-core coil CL is held by each ofthe coil holding portions 56 and 57. However, the invention is notlimited thereto. For example, the air-core coils CL may be fixeddirectly to the first frame 54 and the second frame 55.

In the embodiments, the color combination device 345 is assumed to beconfigured by a cross dichroic prism. However, the invention is notlimited thereto. For example, the color combination device 345 may haveany shape as long as the light incident from the liquid crystal panels341 can be combined.

In the foregoing embodiments, one pair of coil holding portions 56 aredisposed near the corner CR3 in the first frame 54, that is, at thepositions in the Y direction in the opposite direction to the Xdirection when the shift element 5 is viewed in the opposite directionto the Z direction. One pair of coil holding portions 57 are disposednear the corner CR2 in the first frame 54, that is, at the positions inthe opposite direction to the Y direction in the X direction. However,the invention is not limited thereto. For example, the positions of onepair of coil holding portions 56 may be reverse to the positions of onepair of coil holding portions 57. Even in this case, it is possible toobtain the same advantages as those of the shift elements 5, 5A, and 5Baccording to the foregoing embodiments.

In the foregoing embodiments, the branch portions 431 and 451 areinstalled only in the first duct portion 43 and the third duct portion45. However, the invention is not limited thereto. For example, a branchportion may be installed in the second duct portion 44 to supply fromthe branch portion a cooling gas to the shift element 5. In this case,the prism base 347L to which the color combination device 345 is fixedmay not be provided, but a sending port may be configured instead of theconnection portion 46. Thus, since the cooling gas branched from thecooling gas circulated in the first to third duct portions 43 to 45 issupplied to the substantially entire region of the shift element 5, itis possible to cool the shift element 5 more reliably.

In the foregoing embodiments, the pairs of coil holding portions 56, 57,56A, 56B, and 57B hold the air-core coils CL. However, the invention isnot limited thereto. For example, the pairs of coil holding portions 56,57, 56A, 56B, and 57B may hold iron-core coils. That is, any shape andkind of coils may be used as long as a magnetic force can be generatedby supplying power.

In the foregoing embodiments, the rim 52, the first frame 54, the secondframe 55, the pairs of coil holding portions 56, 57, 56A, 56B, and 57Bare formed of aluminum. However, the invention is not limited thereto.For example, the invention is not limited to aluminum, but the rim 52,the first frame 54, the second frame 55, the pairs of coil holdingportions 56, 57, 56A, 56B, and 57B may be formed of any material havingonly to have heat conductivity.

In the foregoing embodiments, the rectification portions 436, 446, and456 are installed at the ends of the protrusions 435, 445, and 455 inthe opposite direction to the Y direction. However, the invention is notlimited thereto. For example, the rectification portions 436, 446, and456 may be internal surface of the exterior casing 2. In this case, theduct member 42 is mounted on the internal surface so that each ductportion can be formed.

In the second embodiment, the coil holding portion 561A includes theextension 56A1. However, the invention is not limited thereto. Forexample, the coil holding portion 562 may include an extension as in thecoil holding portion 561A. Further, the coil holding portions 571 and572 may similarly include extensions. Additionally, the fins 56B1 and57B1 according to the third embodiment may further be included in thecoil holding portions 561A and 562, 571, and 572 including theextensions.

In the third embodiment, the pairs of coil holding portions 56B and 57Ball have heat sink shapes including the fins 56B1 and 57B1. However, theinvention is not limited thereto. For example, the fins 56B1 and 57B1may be installed only in the coil holding portions 561B and 571B mountedon the first frame 54 or the fins 56B1 and 57B1 may be installed only inthe coil holding portions 562B and 572B mounted on the second frame 55.That is, the fins 56B1 and 57B1 may be installed in one of the coilholding portions 561B, 562B, 571B, and 572B.

The shapes of the fins 56B1 and 57B1 are not limited to the rectangularplate shape, but may have any shape. Alternatively, fins havingdifferent shapes may be installed for the respective coil holdingportions 561B, 562B, 571B, and 572B. In short, the heat radiation areaof the coil holding portions 561B, 562B, 571B, and 572B may be enlarged.

In the foregoing embodiments, the transmission type liquid crystalpanels 341 (341R, 341G, and 341B) are used as the light modulationdevices. However, the invention is not limited thereto. For example,reflection type liquid crystal panels may be used instead of thetransmission type liquid crystal panels 341 (341R, 341G, and 341B). Inthis case, color separation and color combination may be performed bythe color combination device 345 without installing the color separationdevice 33.

In the foregoing embodiments, the projector 1 includes the three liquidcrystal panels 341 (341R, 341G, and 341B), but the invention is notlimited thereto. That is, the invention can be applied to a projectorthat uses two or less or four or more liquid crystal panels.

Instead of the liquid crystal panels, digital micromirror devices (DMDs)or the like may be used.

In the foregoing embodiments, the projector 1 includes one pair of lightsource devices 31A and 31B. However, the invention is not limitedthereto. For example, number of light source devices may be one or four.

In the foregoing embodiments, the image forming device 3 is disposed asin FIG. 2. However, the invention is not limited thereto. For example,the image forming device may be disposed in a substantial L shape or asubstantial U shape.

Hereinafter, a fourth embodiment of the invention will be described withreference to the drawings.

Exterior Configuration of Projector

FIG. 15 is a schematic perspective view illustrating a projector 1Caccording to an embodiment of the invention.

The projector 1C according to the embodiment is a projection typedisplay apparatus that modulates light emitted from an illuminationdevice 31 to be described below to form an image according to imageinformation and expands and projects the image to a projection surfacesuch as a screen.

The projector 1C includes a shift element that changes a light path ofincident light, as will be described below in detail. A circulationcooling device has a function of circulating and cooling the shiftelement in addition to a light modulation device to be described below.

As illustrated in FIG. 15, the projector 1C includes an exterior casing2 that forms the exterior appearance.

The exterior casing 2 has a substantially rectangular parallelepipedshape that has a top surface 21, a bottom surface 22, a front surface23, a rear surface 24, and a left side surface 25, and a right sidesurface 26.

In the top surface 21, an opening (not illustrated) is formed todetachably mount light source devices 31A and 31B to be described belowon the inside of the exterior casing 2. The opening is covered with acover member 212.

Although not illustrated, leg portions coming into contact with aninstallation surface of an installation stand when placed on theinstallation surface of the installation stand are installed on thebottom surface 22.

An opening 231 in which a part of the optical projection device 35included in an image forming device 3 to be described below is exposedis formed in the front surface 23.

Although the others are not illustrated, an inlet port introducing anair outside the exterior casing 2 into the inside is formed on the rightside surface 26, and an outlet port discharging the air inside theexterior casing 2 to the outside is formed on the left side surface 25.

Internal Configuration of Projector

FIG. 16 is a schematic diagram illustrating an internal configuration ofthe projector 1C.

The projector 1C includes not only the exterior casing 2 but also animage forming device 3 and a circulation cooling device 4C disposed inthe exterior casing 2, as illustrated in FIG. 16. Additionally, althoughnot illustrated, the projector 1C includes a control device thatcontrols the projector 1C and a power device that supplies power toelectronic components included in the projector 1C.

Configuration of Image Forming Device

The image forming device 3 forms and projects an image according toimage information input from the control device. The image formingdevice 3 includes an illumination device 31, a uniformalization device32, a color separation device 33, an electric optical device 34, anoptical projection device 35, and an optical component casing 36.

Of the devices, the optical component casing 36 is a box-like casing inwhich an illumination light axis Ax is set. The illumination device 31,the uniformalization device 32, and the color separation device 33 aredisposed at positions on the illumination light axis Ax inside theoptical component casing 36. The electric optical device 34 and theoptical projection device 35 are located outside the optical componentcasing 36 and are disposed according to the illumination light axis Ax.

The illumination device 31 includes a pair of light source devices 31Aand 31B which are disposed to face each other and a reflection mirror31C disposed between the pair of light source devices 31A and 31B.

The pair of light source devices 31A and 31B each include a light sourcelamp 311, a reflector 312, and a housing body 313 that houses the lightsource lamp 311 and the reflector 312. The light source devices 31A and31B emit light toward the reflection mirror 31C.

The reflection mirror 31C reflects the light incident from the lightsource devices 31A and 31B in the same direction so that the light isaccordingly incident on the uniformalization device 32.

The uniformalization device 32 uniformalizes illuminance in anorthogonal plane to a central axis of a light flux emitted from theillumination device 31. The uniformalization device 32 includes a cinemafilter 321, a first lens array 322, a UV filter 323, a second lens array324, a polarization conversion element 325, and a superimposition lens326.

Of the elements, the polarization conversion element 325 arrangespolarization directions of the incident light in one kind of direction.

The color separation device 33 separates the light flux incident fromthe uniformalization device 32 into three pieces of color light of red(R), green (G), and blue (B). The color separation device 33 includesdichroic mirrors 331 and 332, reflection mirrors 333 to 336, and relaylenses 337 to 339.

The electric optical device 34 modulates the pieces of separated colorlight according to image information, and then combines the pieces ofmodulated color light. The electric optical device 34 includes fieldlends 340, liquid crystal panels 341 (red, green, and blue liquidcrystal panels are referred to as liquid crystal panels 341R, 341G, and341B, respectively) serving as light modulation devices installed forthe respective pieces of color light, incidence-side polarization plates342, exit-side polarization plates 343, optical compensation plates 344,and one color combination device 345. Of the elements, the colorcombination device 345 corresponds to a light combination deviceaccording to the invention. The light emitted from the color combinationdevice 345 is incident on the shift element 5C to be described below.

The circulation cooling device 4C has a function of cooling the electricoptical device 34 and the shift element 5C.

The shift element 5C increases the resolution of a projection image byperiodically shifting a light path of light emitted by the colorcombination device 345.

A crystal diffusion plate 6 diffuses and exits the light exited from theshift element 5C and incident on the crystal diffusion plate 6 to theoptical projection device 35.

The configurations of the circulation cooling device 4C and the shiftelement 5C will be described below in detail.

The optical projection device 35 is a projection lens that expands thelight flux (which is a light flux forming an image) combined by thecolor combination device 345 and projects the light flux to theprojection surface. An assembled lens in which a plurality of lenses aredisposed in a barrel can be adopted as the optical projection device 35.

Configuration of Shift Element

FIG. 17 is a plan view illustrating the shift element 5C when the shiftelement 5C is viewed from the light incidence side. FIG. 18 is a planview illustrating the shift element 5C when viewed from the light exitside. FIG. 19 is a side view illustrating the shift element 5C. FIG. 20is an exploded perspective view illustrating the shift element 5C.

The shift element 5C corresponds to a light path changing elementaccording to the invention and has a function of changing (shifting) alight path of the light incident on the shift element 5C and exited fromthe shift element 5C. As illustrated in FIGS. 17 to 20, the shiftelement 5C includes an optical member 51, a rim 52C, permanent magnets53, a first frame 54C, a second frame 55C, and pairs of coil holdingportions 56C and 57C.

Of the elements, the optical member 51 is configured as a transparentmember that has transmittance and is configured of a rectangular plateglass in the embodiment.

In the following drawings and description, a travelling direction(projection direction) of the light exited from the color combinationdevice 345 and incident on the shift element 5C is set to a Z direction,and directions orthogonal to the Z direction and orthogonal to eachother are X and Y directions. In the embodiment, an upward side which isan opposite direction to the vertical direction (that is, a directionoriented from the bottom surface 22 to the top surface 21 of theexterior casing 2) is set to the Y direction in a case in which theprojector 1C is disposed so that the Z direction is oriented in thehorizontal direction in a plan view. A direction oriented from the leftto the right when viewed in the Z direction (light traveling direction)(that is, a direction oriented from the left side surface 25 to theright side surface 26 of the exterior casing 2) is set to the Xdirection.

Configuration of Rim

The rim 52C has a function of holding the optical member 51 and thepermanent magnets 53. As illustrated in FIG. 20, the rim 52C isconfigured in a rectangular plate shape that has four corners CR1 toCR4. An opening 521 in which the optical member 51 is inserted is formedin the substantially middle portion of the rim 52C. Fitting grooves 522and 523 in which the permanent magnets 53 are inserted are formed at aposition in the Y direction of the opening 521 of the rim 52C and aposition in the opposite direction to the Y direction. Of the fittinggrooves 522 and 523, the fitting groove 522 is formed in the oppositedirection to the X direction relative to the fitting groove 523.

Positioning protrusions 524 protruding in the opposite direction to theZ direction are formed at end edges in the Y direction of the fittinggroove 522 of the rim 52C and in the opposite direction to the Xdirection. Positioning protrusions 525 protruding in the oppositedirection to the Z direction are formed at end edges in the oppositedirection to the Y direction of the fitting groove 523 of the rim 52Cand in the X direction. Further, positioning protrusions 526 and 527protruding in the Z direction are formed at position corresponding tothe positioning protrusions 524 and 525 on the surface of the rim 52C inthe Z direction.

In other words, the positioning protrusions 524 and 526 in the Ydirection are formed near the corner CR3 among the four corners CR1 toCR4 of the rim 52C. The positioning protrusions 525 and 527 in theopposite direction to the Y direction are formed near the corner CR2which is a diagonal corner of the corner CR3.

As illustrated in FIG. 20, the permanent magnets 53 are formed in arectangular column shape. The permanent magnet 53 (permanent magnet 531)is fitted in the fitting groove 522 and the permanent magnet 53(permanent magnet 532) is fitted in the fitting groove 523. In this way,the permanent magnets 531 and 532 are fixed to the rim 52C.

Configuration of First Frame

The first frame 54C is disposed in the opposite direction to the Zdirection of the rim 52C and has a function of interposing the rim 52Calong with the second frame 55C. The first frame 54C is formed in arectangular plate shape and an opening 541 is formed in thesubstantially middle of the first frame 54C. The opening 541 is formedin substantially the same shape as the optical member 51. Accordingly,light incident from the opening 541 is incident on the optical member51.

Through holes 542 are formed at end edges in the Y direction of thefirst frame 54C and in the opposite direction to the X direction, andthrough holes 543 are formed at end edges in the opposite direction tothe Y direction of the first frame 54C and in the X direction. Thepositioning protrusions 524 of the rim 52C are inserted into the throughholes 542 and the positioning protrusions 525 are inserted into thethrough holes 543.

Configuration of Second Frame

The second frame 55C is disposed in the Z direction of the rim 52C andhas a function of interposing the rim 52C along with the first frame54C. The second frame 55C is formed in a rectangular plate shape and anopening 551 is formed in the substantially middle of the second frame55C. The opening 551 is formed in substantially the same shape as theoptical member 51.

Through holes 552 are formed at end edges in the Y direction of thesecond frame 55C and in the opposite direction to the X direction, andthrough holes 553 are formed at end edges in the opposite direction tothe Y direction of the second frame 55C and in the X direction. Thepositioning protrusions 526 of the rim 52C are inserted into the throughholes 552 and the positioning protrusions 527 are inserted into thethrough holes 553.

In this configuration, the first frame 54C and the second frame 55Cinterpose the rim 52C. The rim 52C, the first frame 54C, and the secondframe 55C correspond to a holding portion according to the invention.

Configuration of Coil Holding Portion

One pair of coil holding portions 56C and one pair of coil holdingportions 57C each include an air-core coil CL corresponding to a coilaccording to the invention therein. When power is supplied to theair-core coil CL, the air-core coil CL displaces the permanent magnet 53and further generates a magnetic force that displaces the shift element5C. Of the portions, one pair of coil holding portions 56C includes acoil holding portion 561C fixed to the first frame 54C and a coilholding portion 562C fixed to the second frame 55C.

Holes 5611 and 5621 are formed in the coil holding portions 561C and562C, respectively. The positioning protrusions 524 of the rim 52C arefitted into the holes 5611 through the through holes 542 of the firstframe 54C. On the other hand, the positioning protrusions 526 of the rim52C are fitted into the holes 5621 through the through holes 552 of thesecond frame 55C. Accordingly, the coil holding portion 561C is fixed tothe first frame 54C and the coil holding portion 562C is fixed to thesecond frame 55C.

One pair of coil holding portions 57C includes a coil holding portion571C fixed to the first frame 54C and a coil holding portion 572C fixedto the second frame 55C. Holes 5711 and 5721 are formed in the coilholding portions 571C and 572C, respectively. The positioningprotrusions 525 of the rim 52C are fitted into the holes 5711 throughthe through holes 543 of the first frame 54C. On the other hand, thepositioning protrusions 527 of the rim 52C are fitted into the holes5721 through the through holes 553 of the second frame 55C. Accordingly,the coil holding portion 571C is fixed to the first frame 54C and thecoil holding portion 572C is fixed to the second frame 55C.

In this way, the coil holding portions 561C and 562C of one pair of coilholding portions 56C are disposed near the corner CR3 in the Y directionin the opposite direction to the X direction and at superimposingpositions and orientation. On the other hand, the coil holding portions571C and 572C of one pair of coil holding portions 57C are disposed nearthe corner CR2 in the X direction and the opposite direction to the Ydirection and at superimposing positions and orientation in a case inwhich the shift element 5C is viewed in the Z direction. In other words,when the shift element 5C is viewed in the opposite direction to the Zdirection, one pair of coil holding portions 56C are disposed on theside of the liquid crystal panel 341B and one pair of coil holdingportions 57C are disposed on the side of the liquid crystal panel 341R.

The rim 52C, the first frame 54C, and the second frame 55C, one pair ofcoil holding portions 56C, and one pair of coil holding portions 57C areformed of metal having heat conductivity and are formed of aluminum inthe embodiment. Accordingly, in a case in which the temperature of theair-core coil CL increases, heat of the rim 52C, the first frame 54C,the second frame 55C, and the air-core coils CL of one pair of coilholding portions 56C and one pair of coil holding portions 57C istransmitted.

Power supply portions (not illustrated) are connected to the coilholding portions 561C, 562C, 571C, and 572C. The power supply portionssupply power to the air-core coils CL via the coil holding portions561C, 562C, 571C, and 572C to displace the permanent magnets 531 and 532and further generate a magnetic force to displace the shift element 5C.

Specifically, when the permanent magnets 531 and 532 mounted on the rim52C are displaced, the shift element 5C is moved in approaching andseparating directions at a rotational angle L1 illustrated in FIGS. 17and 18, so that the angle of the optical member 51 inserted into theopening 521 of the rim 52C is changed.

In other words, by supplying power to the coil holding portions 561C,562C, 571C, and 572C, it is possible to change the light path of thelight incident on the optical member 51 and exited from the opticalmember 51.

Configuration of Circulation Cooling Device

FIG. 21 is a schematic diagram illustrating a schematic configuration ofthe circulation cooling device 4C. In FIG. 21, in order to facilitatethe description, other elements are not illustrated except for a liquidcrystal panel 341G, field lenses 340 corresponding to the liquid crystalpanel 341G, an incidence-side polarization plate 342, an exit-sidepolarization plate 343, and an optical compensation plate 344 includedin the electric optical device 34.

The circulation cooling device 4C includes a sealed casing 41Ccorresponding to an internal casing according to the invention and has afunction of cooling the electric optical device 34 and the shift element5C disposed in the sealed casing 41C. The circulation cooling device 4Cincludes a prism base 42C, a first fan 43C, a second fan 44C, and a heatsink 45C in addition to the sealed casing 41C.

When the shift element 5C is disposed in the sealed casing 41C, heattransmission portions TC1 to TC4 are fixed to the coil holding portions561C, 562C, 571C, and 572C, respectively. The heat transmission portionsTC1 to TC4 are formed of heat transmission sheets having heatconductivity. Therefore, when the temperature of the air-core coil CLincreases, the heat of the coil holding portions 561C, 562C, 571C, and572C is transmitted to the heat transmission portions TC1 to TC4.

Configuration of Sealed Casing

The sealed casing 41C is a box-like casing that accommodates the liquidcrystal panels 341, the incidence-side polarization plate 342, exit-sidepolarization plate 343, the optical compensation plate 344, the colorcombination device 345, and a holding member 346 included in theelectric optical device 34 and the shift element 5C. The sealed casing41C is disposed in the exterior casing 2. The sealed casing 41C has asealed structure in which a gas outside the sealed casing 41C rarelyflows therein. In other words, the liquid crystal panels 341, theincidence-side polarization plate 342, the exit-side polarization plate343, the optical compensation plate 344, the color combination device345, a holding member 346, and the shift element 5C are substantiallysealed in the sealed casing 41C.

The sealed casing 41C includes a top surface 41 a, a bottom surface 41b, a first side surface 41 c, a second side surface 41 d, and third andfourth side surfaces (not illustrated) in the X direction and theopposite direction to the X direction. The sealed casing 41C includes acasing portion 411 formed by the top surface 41 a, the bottom surface 41b, the first side surface 41 c, and the third and fourth side surfacesand includes a plate-shaped portion 412 and a crystal diffusion plate 6formed by the second side surface 41 d.

Of the elements, the casing portion 411 is formed of resin or the like.An opening 4111 is formed in a substantially middle of the first sidesurface 41 c forming the casing portion 411. The field lens 340corresponding to the liquid crystal panel 341G is inserted into theopening 4111. Openings are also formed in the substantially middle ofthe third side surface and in the substantially middle of the fourthside surface. The field lenses 340 corresponding to the liquid crystalpanels 341R and 341B are inserted into the openings. Thus, the pieces ofcolor light separated by the color separation device 33 are incident onthe liquid crystal panels 341 through the field lenses 340.

The plate-shaped portion 412 forms a part of the second side surface 41d of the sealed casing 41C and an opening 4121 is formed in asubstantial middle of the plate-shaped portion 412. The crystaldiffusion plate 6 is inserted into the opening 4121. The plate-shapedportion 412 is formed of a metal having heat conductivity and is formedof aluminum in the embodiment.

The heat transmission portion TC1 comes into contact with a first spot4122 of the plate-shaped portion 412 located in the Y direction so thatheat is transmittable. The heat transmission portion TC2 comes intocontact with a second spot 4123 of the plate-shaped portion 412 locatedin the opposite direction to the Y direction so that heat istransmittable. The prism base 42U is fixed to the first spot 4122 andthe prism base 42L is fixed to the second spot 4123. Therefore, when thetemperature of the air-core coil CL increases, the heat of the coilholding portions 562C and 572C is transmitted to the heat transmissionportions TC1 and TC2, and the heat of the heat transmission portions TC1and TC2 is transmitted to the plate-shaped portion 412.

The first spot 4122 and the second spot 4123 correspond to a heattransmission spot according to the invention.

Configuration of Prism Base

Here, of the constituent elements of the electric optical device 34, theliquid crystal panels 341 (341R, 341G, and 341B), the exit-sidepolarization plate 343, and the optical compensation plate 344 aremounted on the color combination device 345 by the holding member 346 toform an integrated prism unit. The color combination device 345 formingthe prism unit is configured by a substantially quadrangular crossdichroic prism. The color combination device 345 includes threeincidence surfaces on which pieces of light exited from the liquidcrystal panels 341 are separately incident, one exit surface from whichthe light incident from the incidence surfaces and combined is exited,and a first support surface 3451C and a second support surface 3452Cwhich intersect the plurality of incidence surfaces and the exit surfaceand are located to be opposite to each other and are connected to theprism base 42C.

The prism base 42C corresponds to a support member according to theinvention and has a function of fixing the prism unit to the inside ofthe sealed casing 41C by supporting the color combination device 345.The prism base 42C is formed of metal having heat conductivity and isformed of aluminum in the embodiment. The prism base 42C includes aprism base 42U corresponding to a first support portion according to theinvention and a prism base 42L corresponding to a second support portionaccording to the invention.

The prism bases 42U and 42L include support portions 421U and 421L witha substantial L shape and extensions 422U and 422L extending from endsof the support portions 421U and 421L in the Z direction, as illustratedin FIG. 21.

The first support surface 3451C which is a surface of the colorcombination device 345 in the Y direction comes into contact with thesurface of the support portion 421U of the prism base 42U in theopposite direction to the Y direction, and the heat transmission portionTC3 comes into contact with the surface of the support portion 421U inthe Z direction so that heat is transmittable. The end of the extension422U in the Z direction is fixed to the surface of the plate-shapedportion 412 in the opposite direction to the Z direction.

On the other hand, the second support surface 3452C which is a surfaceof the color combination device 345 in the opposite direction to the Ydirection comes into contact with the surface of the support portion421L of the prism base 42L in the Y direction, and the heat transmissionportion TC4 comes into contact with the surface of the support portion421L in the Z direction so that heat is transmittable. The end of theextension 422L in the Z direction is fixed to the surface of theplate-shaped portion 412 in the opposite direction to the Z direction.

In this configuration, the prism unit (the color combination device 345)is fixed to the inside of the sealed casing 41C and the heat from theheat transmission portions TC3 and TC4 is transmitted to the prism bases42U and 42L.

Heat radiation fins may be installed on the surfaces of the prism bases42U and 42L. By installing the heat radiation fins, it is possible toexpand a contact area with the cooling gas discharged from the first fan43C to be described below, and thus it is possible to efficiently coolthe heat transmitted from the heat transmission portions TC3 and TC4.

Configuration of Cooling Fan

The first fan 43C corresponds to apart of the cooling device accordingto the invention and is formed by a sirocco fan. As illustrated in FIG.21, the first fan 43C is disposed on the side of the first side surface41 c on the bottom surface 41 b. The first fan 43C is disposed so that asuction surface 431C is oriented in the Y direction. An exhaust surface432C is disposed to be oriented in the Z direction. Therefore, when thefirst fan 43C is driven, the cooling gas inside the sealed casing 41C issucked from the suction surface 431C and the cooling gas is dischargedfrom the exhaust surface 432C in the Z direction. A part of the coolinggas discharged from the exhaust surface 432C is branched in the Ydirection by a duct (not illustrated) and the branched cooling gas coolsthe liquid crystal panels 341, the incidence-side polarization plate342, the exit-side polarization plate 343, and the like.

The second fan 44C corresponds to a part of a cooling device accordingto the invention and is configured of an axial fan. The second fan 44Cis disposed in the top surface 41 a and the first side surface 41 c inthe sealed casing 41C. The second fan 44C is disposed so that a suctionsurface 441C is oriented in the Y direction. An exhaust surface 442Cfacing the suction surface 441C is disposed to be oriented in theopposite direction to the Y direction. That is, the suction surface 431Cof the first fan 43C and the exhaust surface 442C of the second fan 44Care disposed to face each other. Therefore, when the second fan 44C isdriven, the cooling gas sucked from the suction surface 441C of thesecond fan 44C and present inside the sealed casing 41C is dischargedfrom the exhaust surface 442C to the first fan 43C and the cooling gasis sucked by the first fan 43C.

The first fan 43C and the second fan 44C are configured by a sirocco fanand an axial fan, respectively, but the invention is not limitedthereto. Both of the first fan 43C and the second fan 44C may beconfigured by sirocco fans or may be configured by axial fans.

Configuration of Heat Sink

The heat sink 45C has a function of reducing temperature of a spot towhich the heat sink 45C is connected. The heat sink 45C is connected tothe top surface 41 a of the sealed casing 41C. Thus, the cooling gascirculated in a position facing the heat sink 45C in the sealed casing41C is cooled by the heat sink 45C.

Circulation Flow Passage of Cooling Gas

When the first fan 43C is driven in the circulation cooling device 4Chaving such a configuration, the cooling gas sucked from the suctionsurface 431C is discharged from the exhaust surface 432C and iscirculated along the bottom surface 41 b. The cooling gas circulatedalong the bottom surface 41 b collides against the second side surface41 d and is circulated in the Y direction, that is, toward the topsurface 41 a. During the circulation of the cooling gas from the bottomsurface 41 b to the top surface 41 a, the shift element 5C, the prismbases 42U and 42L, the prism unit, and the plate-shaped portion 412 arecooled by the cooling gas. Then, the cooling gas cooling the shiftelement 5C, the prism bases 42U and 42L, the prism unit, and theplate-shaped portion 412 is circulated along the top surface 41 a bysuction from the suction surface 441C of the second fan 44C. During thiscirculation, the cooling gas is cooled by the heat sink 45C and issucked to the second fan 44C. Then, the cooling gas is discharged fromthe exhaust surface 442C of the second fan 44C to the first fan 43C andis sucked from the suction surface 431C of the first fan 43C.

As described above, the cooling gas inside the sealed casing 41C iscirculated clockwise by driving the first fan 43C and the second fan44C. In this way, the plate-shaped portion 412 to which the heat fromthe coil holding portions 562C and 572C and the heat transmissionportions TC1 and TC2 is transmitted is cooled. Further, the prism bases42U and 42L to which the heat from the coil holding portions 561C and571C and the heat transmission portions TC3 and TC4 is transmitted arecooled. Thus, the heat transmitted from the air-core coil CL is radiatedand the air-core coil CL is thus cooled.

The projector 1C according to the above-described embodiment has thefollowing advantages.

Since the plurality of liquid crystal panels 341R, 341G, and 341B, theshift element 5C, and the color combination device 345 are disposed inthe sealed casing 41C, it is possible to prevent dust from beingattached to the liquid crystal panels 341, the color combination device345, and the shift element 5C. Accordingly, it is possible to improveluminance and saturation of an image to be projected from the projector1C.

Here, when power is supplied to one pair of air-core coils CL disposedwith the permanent magnet 53 interposed therebetween, the permanentmagnet 53 is displaced, and thus the magnetic force displacing the shiftelement 5C is generated and the temperature of the one pair of air-corecoils CL is increased. When the temperature of the one pair of air-corecoils CL is increased in this way, the magnetic force of the one pair ofair-core coils CL generating the magnetic force is weakened in somecases.

In contrast, in the embodiment, the heat transmission portions TC1 toTC4 fixed to the coil holding portions 561C, 562C, 571C, and 572C of theshift element 5C come into contact with the prism base 42C serving as asupport member. Therefore, when the heat of the air-core coils CL isincreased, the heat of the air-core coils CL is transmitted to thesupport member via the heat transmission portions. Thus, it is possibleto prevent the temperature of one pair of air-core coils CL included inthe shift element 5C from being increased. Accordingly, since it ispossible to prevent the magnetic force of the air-core coils CLinstalled in the shift element 5C from being reduced, it is possible tostabilize driving of the shift element 5C.

The support portions 421U and 421L supporting the first support surface3451C and the second support surface 3452C of the color combinationdevice 345 come into contact with the heat transmission portions TC3 andTC4. Therefore, when the heat of the air-core coils CL is increased, theheat of the air-core coils CL is transmitted to the prism base 42C viathe heat transmission portions TC3 and TC4. Thus, it is possible toprevent the temperature of one pair of air-core coils CL included in theshift element 5C from being increased. Accordingly, since it is possibleto prevent the magnetic force of the air-core coils CL installed in theshift element 5C from being reduced, it is possible to stabilize drivingof the shift element 5C.

The heat transmission portions TC1 and TC2 come into contact with thesealed casing 41C, more specifically, the first spot 4122 and the secondspot 4123 having heat conductivity in the sealed casing 41C so that heatis transmittable. When the heat of the air-core coils CL is increased,the heat of the air-core coils CL is transmitted to the plate-shapedportion 412 of the sealed casing 41C via the heat transmission portionsTC1 and TC2. Thus, it is possible to reliably prevent the temperature ofone pair of air-core coils CL included in the shift element 5C frombeing increased. Accordingly, since it is possible to reliably preventthe magnetic force of the air-core coils CL installed in the shiftelement 5C from being reduced, it is possible to reliably stabilizedriving of the shift element 5C.

Since the first fan 43C is disposed as the cooling device in the sealedcasing 41C, it is possible to cool the liquid crystal panels 341, theshift element 5C, and the color combination device 345 disposed in thesealed casing 41C. Since the cooling gas is circulated to the prism base42C to which the heat of the air-core coils CL is transmitted via theheat transmission portions TC1 to TC4, it is possible to reliably coolthe prism base 42C. Accordingly, it is possible to prevent thetemperature of one pair of air-core coils CL included in the shiftelement 5C from being increased.

Modifications of Embodiment

The invention is not limited to the foregoing embodiments, butmodifications, improvement, and the like are included in the inventionwithin the scope of the invention.

In the foregoing embodiment, the shift element 5C, the color combinationdevice 345, and the liquid crystal panels 341 are disposed in the sealedcasing 41C. However, the invention is not limited thereto. For example,only the shift element 5C may be disposed in the sealed casing 41C oronly the shift element 5C and the liquid crystal panels 341 may bedisposed in the sealed casing 41C. In summary, the shift element 5C maybe disposed in the sealed casing 41C.

In the foregoing embodiment, the sealed casing 41C is substantiallysealed. However, the invention is not limited thereto. For example, thesealed casing 41C may not be sealed or may be configured to supply thecooling gas from a spot which is not sealed.

In the foregoing embodiment, the heat transmission portions TC1 to TC4are fixed to the coil holding portions 561C, 562C, 571C, and 572C.However, the invention is not limited thereto. For example, the heattransmission portions TC1 to TC4 may not be included and the coilholding portions 561C, 562C, 571C, and 572C may be configured to comeinto contact with the prism base 42C and the plate-shaped portion 412 sothat heat is directly transmittable. Even in this case, it is possibleto obtain the same advantages as those of the forgoing embodiment.

In the foregoing embodiment, the heat transmission portions TC1 to TC4are formed of heat transmission sheets having heat conductivity.However, the invention is not limited thereto. For example, the heattransmission portions TC1 to TC4 may be configured of grease or the likehaving heat conductivity without being limited to solid. That is, theheat transmission portions TC1 to TC4 may be formed of any material aslong as the material has heat conductivity.

In the foregoing embodiment, the first spot 4122 and the second spot4123 of the plate-shaped portion 412 with which the heat transmissionportions TC1 and TC2 come into contact so that heat is transmittablehave the heat conductivity. However, the invention is not limitedthereto. For example, the plate-shaped portion 412 may be formed ofresin or the like.

In the foregoing embodiment, the heat transmission portions TC1 and TC2come into contact with the plate-shaped portion 412 so that heat istransmittable. However, the invention is not limited thereto. Forexample, only the heat transmission portion TC1 may come into contactwith the plate-shaped portion 412 so that heat is transmittable or onlythe heat transmission portion TC2 may come into contact with theplate-shaped portion 412 so that heat is transmittable. In this case, inthe heat transmission portions TC1 and TC2, a spot which does not comeinto contact with the plate-shaped portion 412 so that heat istransmittable may be formed of a material having no heat conductivity.

In the foregoing embodiment, the circulation cooling device 4C includesthe first fan 43C and the second fan 44C. However, the invention is notlimited thereto. For example, the circulation cooling device 4C mayinclude one of the first fan 43C and the second fan 44C. Even in thiscase, it is possible to cool the liquid crystal panels 341, the colorcombination device 345, and the shift element 5C disposed in the sealedcasing 41C. The first pan 43C and the second fan 44C may not be presentin the sealed casing 41C. In this case, for example, the heat sink maycome into contact with a portion other than the sealed casing 41C sothat the cooling is performed by a cooling fan from the portion otherthan the sealed casing 41C.

In the foregoing embodiment, the heat sink 45C included in thecirculation cooling device 4C is connected to the top surface 41 a.However, the invention is not limited thereto. For example, the heatsink 45C may be installed on any of the bottom surface 41 b, the firstside surface 41 c, and the second side surface 41 d. Further, the numberof heat sinks 45C may not be one, the heat sinks 45C may be installed onthe bottom surface 41 b, the first side surface 41 c, and the secondside surface 41 d, or the heat sink 45C may not be installed.

In the foregoing embodiment, the prism bases 42U and 42L are included.However, the invention is not limited thereto. For example, only one ofthe prism bases 42U and 42L may be included. In particular, when onlythe prism base 42U is included, it is possible to further circulate thecooling gas from the bottom surface 41 b to the shift element 5C.

In the foregoing embodiment, the first support surface 3451C and thesecond support surface 3452C supported by the prism bases 42U and 42Lare the surface in the Y direction of the color combination device 345and the surface in the opposite direction to the Y direction. However,the invention is not limited thereto. For example, the prism bases 42Uand 42L may support the surface of the color combination device 345 inthe X direction and the surface in the opposite direction to the Xdirection. In this case, the liquid crystal panels 341R and 341B servingas the light modulation device may be disposed to face the first supportsurface 3451C and the second support surface 3452C.

In the foregoing embodiment, the shift element 5C includes the opticalmember 51, the rim 52C, the permanent magnet 53, the first frame 54C,the second frame 55C, and one pair of coil holding portions 56C and 57C.However, the invention is not limited thereto. For example, the firstframe 54C and the second frame 55C may be integrated. One pair of coilholding portions 56C and one pair of coil holding portions 57C areincluded, but only one pair of coil holding portions may be included.

That is, any configuration can be used as long as power can be suppliedto the air-core coils CL held by the coil holding portions 56C and 57C,the optical member 51 can be fluctuated, and the light path of the lightincident on the optical member 51 can be changed.

In the foregoing embodiment, the shift element 5C has the configurationillustrated in FIGS. 17 to 20. However, the invention is not limitedthereto. For example, any configuration may be used as long as theoptical member 51 can be fluctuated by a solenoid or the like and thelight path of the incident light can be changed.

In the foregoing embodiment, the second side surface 41 d is formed bythe plate-shaped portion 412 and the crystal diffusion plate 6. However,the invention is not limited thereto. For example, the second sidesurface 41 d may be formed by a transparent member that merely passesthe light from the shift element 5C, instead of the crystal diffusionplate 6.

In the foregoing embodiment, the air-core coils CL are held by the coilholding portions 56C and 57C. However, the invention is not limitedthereto. For example, the air-core coils CL may be configured to bedirectly fixed to the first frame 54C and the second frame 55C.

In the foregoing embodiment, the color combination device 345 isconfigured by the cross dichroic prism. However, the invention is notlimited thereto. For example, the color combination device 345 may haveany shape as long as the light incident from the liquid crystal panels341 can be combined.

In the foregoing embodiment, one pair of coil holding portions 56C aredisposed near the corner CR3 in the first frame 54C, that is, at thepositions in the Y direction in the opposite direction to the Xdirection when the shift element 5C is viewed in the opposite directionto the Z direction. One pair of coil holding portions 57C are disposednear the corner CR2 in the first frame 54C, that is, at the positions inthe opposite direction to the Y direction in the X direction. However,the invention is not limited thereto. For example, the positions of onepair of coil holding portions 56C may be reverse to the positions of onepair of coil holding portions 57C.

In the foregoing embodiment, the pairs of coil holding portions 56C and57C hold the air-core coils CL. However, the invention is not limitedthereto. For example, the pairs of coil holding portions 56C and 57C mayhold iron-core coils. That is, any shape and kind of coils may be usedas long as a magnetic force can be generated by supplying power.

In the foregoing embodiment, the rim 52C, the first frame 54C, thesecond frame 55C, the pairs of coil holding portions 56C and 57C areformed of aluminum. However, the invention is not limited thereto. Forexample, the invention is not limited to aluminum, but the rim 52C, thefirst frame 54C, the second frame 55C, the pairs of coil holdingportions 56C and 57C may be formed of any material having only to haveheat conductivity.

In the foregoing embodiment, the transmission type liquid crystal panels341 (341R, 341G, and 341B) are used as the light modulation devices.However, the invention is not limited thereto. For example, reflectiontype liquid crystal panels may be used instead of the transmission typeliquid crystal panels 341 (341R, 341G, and 341B). In this case, colorseparation and color combination may be performed by the colorcombination device 345 without installing the color separation device33.

In the foregoing embodiment, the projector 1C includes the three liquidcrystal panels 341 (341R, 341G, and 341B), but the invention is notlimited thereto. That is, the invention can be applied to a projectorthat uses two or less or four or more liquid crystal panels.

Instead of the liquid crystal panels 341, digital micromirror devices(DMDs) or the like may be used.

In the foregoing embodiment, the projector 1C includes one pair of lightsource devices 31A and 31B. However, the invention is not limitedthereto. For example, the number of light source devices may be one orfour.

In the foregoing embodiment, the image forming device 3 is disposed asin FIG. 16. However, the invention is not limited thereto. For example,the image forming device may be disposed in a substantial L shape or asubstantial U shape.

What is claimed is:
 1. A projector comprising: a light source; a lightmodulation device that modulates light emitted from the light source; anoptical projection device that projects the light modulated by the lightmodulation device; a light path changing element that is disposedbetween the light modulation device and the optical projection deviceand changes a light path of the light modulated by the light modulationdevice through fluctuation; and a cooling device that cools the lightmodulation device and the light path changing element.
 2. The projectoraccording to claim 1, further comprising: a plurality of the lightmodulation devices; and a light combination device that combines andexits pieces of light modulated by the plurality of light modulationdevices, wherein the optical projection device projects the light exitedfrom the light combination device, and wherein the light path changingelement is disposed between the light combination device and the opticalprojection device.
 3. The projector according to claim 2, wherein thecooling device includes a cooling fan that sends a cooling gas and aduct member that circulates the cooling gas from the cooling fan in theplurality of light modulation devices, and wherein the duct memberincludes a sending port that circulates the cooling gas toward the lightpath changing element.
 4. The projector according to claim 3, whereinthe light path changing element includes a permanent magnet, an opticalmember that changes the light path of the light fluctuated and incidentby the permanent magnet, a holding portion that holds the optical memberand the permanent magnet, and a pair of coils that are disposed in theholding portion with the permanent magnet interposed therebetween. 5.The projector according to claim 4, wherein the light path changingelement includes a coil holding portion holding the one pair of coilsand mounted on the holding portion, and wherein the sending portcirculates at least a part of the cooling gas in the coil holdingportion.
 6. The projector according to claim 5, wherein the coil holdingportion includes a heat radiation portion.
 7. The projector according toclaim 5, wherein the coil holding portion includes an extensionextending toward the sending port.
 8. The projector according to claim3, wherein the light combination device includes three incidencesurfaces on which the light via the plurality of light modulationdevices is incident, and one exit surface through which the lightincident from the three incidence surfaces and combined is exited,wherein the duct member includes a plurality of ducts that are installedto correspond to the plurality of light modulation devices and send thecooling gas circulated inside to the corresponding light modulationdevices, and wherein, of the plurality of ducts, the ducts correspondingto the light modulation devices disposed to be opposite to each otherwith the light combination device interposed therebetween each include abranch portion that branches the cooling gas circulated inside and sendsthe cooling gas from the sending port.
 9. The projector according toclaim 8, wherein the light path changing element includes twofluctuation members including the permanent magnet and the one pair ofcoils, wherein, of the light modulation devices disposed to be oppositeto each other with the light combination device interposed therebetween,one of the fluctuation members is disposed on a side of one lightmodulation device and the other fluctuation member is disposed on a sideof the other light modulation device, and wherein the one fluctuationmember is disposed at a position opposite to the other fluctuationmember with the optical member interposed therebetween when viewed in anincidence direction of light on the optical member.
 10. A projectorcomprising: a light source; a light modulation device that modulateslight emitted from the light source; an optical projection device thatprojects the light modulated by the light modulation device; a lightpath changing element that is disposed between the light modulationdevice and the optical projection device and changes a light path of thelight modulated by the light modulation device through fluctuation; anexterior casing that forms an exterior, and an internal casing in whichthe light path changing element is disposed.
 11. The projector accordingto claim 10, wherein the light modulation device is disposed in theinternal casing.
 12. The projector according to claim 10, furthercomprising: a plurality of the light modulation devices; and a lightcombination device that combines and exits pieces of light modulated bythe plurality of light modulation devices, wherein the opticalprojection device projects the light exited from the light combinationdevice, and wherein the light combination device is disposed in theinternal casing.
 13. The projector according to claim 12, furthercomprising: a support member that is disposed in the internal casing andsupports the light combination device, wherein the light path changingelement includes a permanent magnet, an optical member that changes thelight path of the light fluctuated and incident by the permanent magnet,a holding portion that holds the optical member and the permanentmagnet, a pair of coils that are disposed in the holding portion withthe permanent magnet interposed therebetween, a coil holding portionthat holds the one pair of coils, and a heat transmission portion thatcomes into contact with the coil holding portion, and wherein the heattransmission portion comes into contact with the support member so thatheat is transmittable to the support member.
 14. The projector accordingto claim 13, wherein the internal casing is a sealed casing, wherein thelight combination device includes first and second support surfaces thatare located to be opposite to each other and are connected to thesupport member, wherein the support member includes a first supportportion connected to the first support surface and a second supportportion connected to the second support surface, and wherein the heattransmission portion comes into contact with at least one of the firstand second support portions so that heat is transmittable.
 15. Theprojector according to claim 13, wherein the heat transmission portioncomes into contact with the internal casing so that heat istransmittable.
 16. The projector according to claim 15, wherein theinternal casing includes a heat transmission spot coming into contactwith the heat transmission portion.
 17. The projector according to claim13, further comprising: a cooling device that is disposed in theinternal casing and circulates a cooling gas in the internal casing,wherein a part of the cooling gas is circulated in the support member.